Albert l



(No Model.)

A. L. PARGELLE.

PENDULUM FORULOGKS.

No. 883,589. Patented Ma 29 1888.

N. PETERS. PhnloLfllmgmphl-r; Washinglnn, n. c.

bration required in a clock. To operate at the same rate ornumber of beats as a gravitypendulum,it may belonger orshorter than such a pendulum. It is not governed by the same laws that control an ordinary pendulum, but is dependent upon two conditions-namely, its length and thickness. Gravity does not primarily control its action, as its own inherent resilience serves to return it to the center of vibration or perpendicular position.

Myimproved pendulum is preferably equipped with a bob, which may be a hollow cylindrical cup adapted for the reception of sand or shot or any other suitable weighting material. The bob may be adjusted for regulation in the ordinary way by a thumb-nut on the screwrod extension of the pendulum. A bob may or may not be used. Its effect would be to add steadiness; but it may be dispensed with or a very light one used, according to the'material used for the pendulum. Where a bob is employed it will very slightly, according to its weight, modify the are.

The pendulum may be compensated by any of the ordinary methods, but has the advantage of being partially self-compensating. A change of temperature which would elongate it would also tend to increase its thickness. This automatic compensation is sufficient for ordinary clocks.

The diagram view, Fig. 3, illustrates the character of the are described by such a pend ulum as that shown. 00 represents a base or tangential line, y the are described by an ordinary pendulum, and z the are described by my improved pendulum.

My invention is distinguished from ordinary clock pendulums having suspension springs formed separately or by drawing down the end ofa wire pendulum. Such suspension springs serve merely as hinges upon which the pendulumwhich is a gravity-pendulum-vibrates. In myimproved device the pendulum proper bends in its length in vibrating. and when I use the term bends or bending in its length I mean the rod, strip, or bar forming the pendulum proper bends in vibrating to such extent as to give it the character of an elastic vibrator, as herein set forth, as distinguished from the bending of a mere suspension-spring, for by forming the pendulum of resilient material and causing it to bend in vibrating, it is governed, at least in part, by the laws governing elastic vibrators, and is to that extent different from ordinary gravity spring-suspended pendulums. Preferably the spring-pendulum is made to bend throughout its entire length, as more perfect results are believed to be attained thereby.

In an application for patent heretofore filed by me,and patented April 12, 1887 ,No.360,903, I have shown a pendulum of the character herein described actuated electrically, and have claimed it. I therefore disclaim herein any subject-matter claimed in said patent.

I claim- 1. The combination, substantially as set forth, of a driven train, a pendulum formed of a bar or strip of resilient material rigidly held at its upper end and bending in its length as it vibrates, and a scapement interposed between the pendulum and the clock-train.

2. A pendulum substantially such as herein described, formed of a flat elongated strip of resilient material adapted to be rigidly held at one .end in its support and capable of bending in its length.

3. A pendulum substantially such as herein illustrated, consisting of a bar or strip of resilient material of uniform or substantially uniform cross-section rigidly held at its upper end in its support and bending in its length as it vibrates.

4. A pendulum substantially such as herein described, consisting of a bar or strip of resilient material rigidly held in its support at its upper end, having a suitable bob, and capable of bending in its length as it vibrates.

5. The combination, substantially as set forth, of a driven train, a pendulum formed of a bar or strip of resilient material capable of bending throughout its entire length as it vibrates, and a scapement interposed between the pendulum and train.

ALBERT L. PARCELLE.

Witnesses:

T. F. HASCALL, WV. W. WHEELooK. 

